Raw pet food as a risk factor for shedding of extended-spectrum beta-lactamase-producing Enterobacteriaceae in household cats

Abstract

BackgroundClose contact between pets and owners provides the opportunity for transmission of antimicrobial resistant organisms like extended-spectrum beta-lactamase (ESBL)/AmpC beta-lactamase (AmpC)-producing Enterobacteriaceae, posing a risk to public health.ObjectivesTo investigate whether raw feed is a risk factor for household cats to shed ESBL-producing Enterobacteriaceae, a cohort study was designed. Additionally, raw and non-raw commercial pet food products were screened for the presence of ESBL-producing Enterobacteriaceae.MethodsWeekly fecal samples of 17 cats in the control group and 19 cats in the exposed group were collected for three weeks and analyzed for the presence of ESBL-producing Enterobacteriaceae. Questionnaires were obtained to determine additional risk factors. Fecal samples were cultured on MacConkey agar supplemented with 1 mg/L cefotaxime. PCR and sequence analysis was used for screening for ESBL genes in suspected isolates. Pet food samples were cultured in LB broth supplemented with 1 mg/L cefotaxime and processed as described above.ResultsIn the cohort study, ESBL-producing bacteria were isolated from 3 of 51 (5.9%) samples in the control group compared to 37 of 57 (89.5%) samples in the exposed group. A significant association was found between ESBL shedding and feeding raw pet food products (OR = 31.5). No other risk factors were identified in this study. ESBL-producing Enterobacteriaceae were isolated from 14 of 18 (77.8%) raw pet food products and 0 of 35 non-raw pet food products.ConclusionsThis study shows a strong association between shedding of ESBL-producing bacteria in household cats and feeding raw pet food. Raw pet food was often contaminated with ESBL-producing Enterobacteriaceae.

Raw diets for dogs and cats: a review, with particular reference to microbiological hazards

“…A study in the Netherlands reported that 28 of 35 raw pet food products yielded ESBL-positive E. coli (van Bree et al 2018), while in Italy, ESBL producers were prevalent among Salmonella isolates from date-expired human products available for pet food use (Bacci et al 2019). A second Dutch study also found that a similar proportion of raw products (14 of 18) yielded ESBL-or AmpC-positive Enterobacteriaceae compared with none of 35 processed products (Baede et al 2017), whilst 23% of Nordic raw food samples containing poultry meat yielded plasmid-borne AmpC genes (Nilsson 2015).…”

Antimicrobial Resistance on Farms: A Review Including Biosecurity and the Potential Role of Disinfectants in Resistance Selection

“…On livestock units such animals may be used for stock management, pest control, or as companions. AMR bacteria ( E. coli or Salmonella ) have readily been isolated from uncooked pet food or treats (Baede et al., ; Nilsson, ; Pitout et al., ). Furthermore, raw feeding has been identified as a risk factor for the fecal shedding of: multidrug resistant E. coli (Groat, Williams, Pinchbeck, Simpson, & Schmidt, , p. 540), E. coli resistant to extended‐spectrum cephalosporin antimicrobials (Baede et al., ; Groat et al., , p. 540; Lefebvre, Reid‐Smith, Boerlin, & Weese, ), and antimicrobial‐resistant Salmonella (Leonard et al., ).…”

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“…The foregoing findings may be considered with the high counts of Enterobacteriaceae often encountered in raw foods, plus study evidence of a low incidence of ESBL/AmpC phenotype enteric organisms from heat-treated food (Baede et al 2017). Taken together, this indicates that raw feeding may elevate the risk of the multiplication and dissemination of such antimicrobial resistances.…”

“…There is particular concern currently over the spread of extended-spectrum beta-lactamase (ESBL) resistance genes, typically borne on transmissible plasmids, which confer reduced susceptibility to the higher generation cephalosporins that are considered of critical importance in human medicine. Members of Enterobacteriaceae bearing ESBL and/or the related AmpC-type resistance have been found to be prevalent among raw pet foods in studies conducted in the Netherlands, Italy and the Nordic countries (Baede et al 2017;Nilsson 2015;van Bree et al 2018).…”

“…Taken together, this indicates that raw feeding may elevate the risk of the multiplication and dissemination of such antimicrobial resistances. Indeed, longitudinal studies in Canada and the Netherlands have found associations between raw fed dogs or cats and the shedding of ESBL and/or AmpCbearing Enterobacteriaceae (Baede et al 2017(Baede et al , 2015Lefebvre et al 2008). These findings have been supported by three recent cross-sectional studies of dogs in the UK (Groat et al 2016;Schmidt et al 2015;Wedley et al 2017).…”